In typical wireless communication networks, also known as cellular radio networks, user equipment communicate via a radio access network to one or more core networks. The user equipments may be mobile telephones or other mobile units with wireless capability, e.g. mobile terminals, laptops, car-mounted mobile devices which communicate voice and/or data with the radio access network.
The radio access network covers a geographical area which is divided into cell areas, with each cell area being served by a base station, known as e.g., eNodeB, eNB, or RBS. A cell is a geographical area where radio coverage is provided by the radio base station equipment at the base station site. The base stations communicate over the air interface with the user equipments within range of the base stations; operating on radio frequencies. Each radio base station in the access network has a limited budget of radio transmission resources that may be used to provide radio/wireless connectivity.
Long Term Evolution (LTE) is a fourth generation mobile communication system, following the Global System for Mobile Communications (GSM) and Wideband Code Division Multiple Access (WCDMA).
Scheduling is a key function to manage the limited radio resources in the radio access network. The scheduling functionality is typically included in a scheduler located in each base station. Each scheduler includes a radio resource management mechanism that is used to allocate radio resources to user equipment in the corresponding cell. The scheduler selects the user equipment to be scheduled and distributes the available transmission resources, such as frequency and time slots, to different user equipment.
The scheduler may base the scheduling decisions on some sort of priority or weight that changes over time based on for example the time since a user equipment last was scheduled or the current radio conditions. Some radio access technologies, e.g., E-UTRAN and UTRAN, include scheduling functionality supporting dynamic scheduling of uplink (UL) and/or downlink (DL) data. The communication from the base station to the user equipment is performed on downlink (DL) and the communication from the user equipment to the base station is performed on uplink (UL).
The transmission resources may be assigned to users and radio bearers according to the users' momentary traffic demand, QoS requirements, and estimated channel quality. Conventional scheduling include efficiency-driven scheduling promoting a high data volume, fairness-driven scheduling promoting a sequential scheduling in accordance to the time of request for a service, or priority-driven scheduling according to assigned priorities for requesting user equipment or the requested services. In a fully loaded network, it will not be possible to schedule radio resources to all requesting user equipment.
Although many different scheduling methods are available today, the known solutions are inadequate in many aspects. While standardization has introduced a framework for service differentiation in the scheduling of different services, scheduling methods at hand are inflexible and do not support dynamical value oriented resource assignment, aiming at maximizing user and/or operator value at every time.